The vortex effect is the cause of vortices being generated on structures exposed to the circulation of a fluid which manifests in the form of vibrations. This effect is caused by the impacting wind and particularly affects the last section of towers when they have no nacelle due to repair and assembly work.
On these occasions, the vibrations may coincide with the natural frequencies of the tower thus amplifying the oscillations of the structure to the point of endangering the tower itself.
A comparison between existing patents and the subject of the present invention has resulted in infinity of methods for tackling the vortex effect issue although none of the studied patents are based on the use of a provisional tool. The most relevant patents obtained from the state of the art study are:
U.S. Pat. No. 4,180,369 incorporating a rigid metal helical strip on the tower itself, which does not have provide an option for removal and makes the manufacture of the tower itself more expensive.
Patent WO9819018 improves on the aforementioned patent using flexible materials screwed to the element requiring protection. The main difference is that these helices are designed to work underwater.
Patent JP2000265708 incorporates a large number of rods fixed by rings and arranged around the tower.
And finally, U.S. Pat. No. 3,581,449 equips the tower with rings and protruding elements, patent GB2362938 has semi-spherical protruding elements and U.S. Pat. No. 4,059,129 installs plates of different shapes.
It is understood from the aforementioned, that none of the analysed patents are similar to the tool for preventing the vortex effect which is the subject of this invention, one may also conclude that said tool is novel as it unhooks a corrugated tubular structure from the upper part of the wind turbine tower to be extended helically, due to its method for anchoring the tool structure to the tower and securing the same one extended, and also due to this being a provisional solution used during the period in which the tower does not have the nacelle installed.